Apparatus for automatic control of exhaust pressure of an internal combustion  engine

ABSTRACT

The present invention relates to an apparatus for automatic control of the exhaust pressure of an internal combustion engine. The apparatus includes: a body having an inlet and an outlet for exhaust gas; a pressure control plate, which is a thin plate placed between the inlet and outlet inside the body, designed to rotate along a vertical direction with respect to the ground, within a particular range of angles; a rotational shaft, which is a bar coupled to one side of the pressure control plate that allows it to have a substantial vertical-rotation movement; first and second side elements, attached on both sides of the body&#39;s exterior and affixed to the protruding part of the rotational shaft extending outward through the holes on both sides; a controlling pendulum coupled to the first side element for setting the initial gradient of the pressure control plate; and a pendulum blade, coupled to a lower portion of the controlling pendulum, which moves in vertical rotation within a particular range of angles by means of air resistance generated during the operation of a vehicle and which, interlocked with the vertical rotational movement, causes the pressure control plate to move in vertical rotation also.

TECHNICAL FIELD

The present invention relates to an apparatus for automaticallycontrolling the exhaust pressure of an internal combustion engine, moreparticularly to an apparatus for automatically controlling the exhaustpressure of an internal combustion engine that creates an optimalexhaust pressure environment according to the output of the internalcombustion engine by automatically controlling how far the exhaustpassage is opened and closed, by way of a pressure control plateconfigured to rotate within a particular range of angles incorrespondence with the speed of the vehicle.

BACKGROUND ART

The general four-stroke cycle of an internal combustion engine consistsof intake, compression, explosion, and exhaust, in that order. Withreference to the stroke continuing from exhaust to intake, the inletvalve opens and the outlet valve closes at the time of intake; however,for a very short time before the outlet valve closes, there exists avalve overlap time during which both the inlet and outlet valves areopen. This is because only with the valve overlap can residual gas beexpelled quickly and a fresh intake of air flow in.

When an internal combustion engine is running at a low speed, increasingthe exhaust pressure can conserve fuel and enhance output.

One reason for this is that, when the aforementioned valve overlapoccurs, the combustion gas is not expelled quickly during the downwardmovement of the piston, and the residual gas applies a downward forceand increases the rotational torque. The efficiency of the engine can beincreased as any incompletely combusted fuel may be recombusted.

However, when an internal combustion engine is running at a high speed,because the piston is making an alternating motion at a very fast speed,a high exhaust pressure can actually be an obstacle to the lift of thepiston in the last stage of the valve overlap.

Consequently, the internal combustion engine can be expected to increaseengine efficiency and enhance output if the exhaust pressure is raisedduring low-speed rotation and lowered during high-speed rotation.

However, for the exhaust pipe of an internal combustion engine installedin general vehicles, the diameter of the exhaust pipe is determined onthe basis of the engine displacement at the point of greatest outputduring the explosion stroke.

Accordingly, when the internal combustion engine is running at a lowspeed, the size of the exhaust pipe is larger than is necessary comparedto the engine displacement, and therefore the exhaust pressure is lower.Thus, a great deal of fuel is incompletely combusted and exhaustedduring the valve overlap, causing the engine's output to decrease.

In other words, the exhaust system of an internal combustion engineaccording to the related art does not include a means to adjust theexhaust pressure to the output of the internal combustion engine incorrespondence with the valve overlap, because it uses an exhaust pipeof a fixed size, and thus has the problem of consuming more fuel than isnecessary and of decreasing the engine's output, especially duringlow-speed rotation.

Certain methods have been suggested in the related art aimed atresolving the problem above, such as of utilizing an exhaust pressuresensor, motor, and driving gear to automatically control the amount bywhich an exhaust valve is opened and closed according to the exhaustpressure detected by the sensor, or utilizing multiple exhaust pipes ofdiffering sizes so as to vary the exhaust path according to exhaustpressure.

These methods, however, do not entail simple structures and require thereplacement of the entire exhaust pipe for installation, and inparticular, substantially increases cost due to additional attachmentssuch as a detector sensor.

DISCLOSURE Technical Problem

The present invention was conceived in order to solve such problems asthe aforementioned, and its purpose is to provide an apparatus forautomatic control of exhaust pressure that can automatically control theamount by which the exhaust passage is opened and closed incorrespondence to the exhaust pressure, so as to increase the exhaustpressure during low-speed rotation and lower the exhaust pressure duringhigh-speed rotation, and thereby enhance the efficiency of the engine.

Another purpose of the present invention is to provide an apparatus forautomatic control of exhaust pressure that can be easily attached to anddetached from an existing exhaust pipe installed in a vehicle, has a lowrate of failure from having a simple structure, can be installedconveniently, and has a low cost of production.

Technical Solution

To achieve the objectives above, an embodiment of the present inventionprovides an apparatus for automatic control of exhaust pressure of aninternal combustion engine. The apparatus includes: a body that isinserted into a middle region of an exhaust pipe, where the bodyincludes an inlet formed on one side and an outlet formed on the otherside opposite the inlet, with the inlet configured to receive exhaustgas emitted from the internal combustion engine and the outletconfigured to expel the received exhaust gas to the outside; a pressurecontrol plate shaped as a thin plate that is placed inside the bodybetween the inlet and the outlet and configured to be capable ofrotational movement within a particular range of angles along a verticaldirection with respect to a ground surface; a rotational shaft shaped asa bar and coupled to an edge of the pressure control plate to enable asubstantial vertical-rotation movement of the pressure control plate,where the rotational shaft has portions thereof protruding through holesformed in both sides of the body; a first side element and a second sideelement included on both sides of the exterior of the body and coupledto protruding portions of the rotational shaft that extend outward tothe outside through the holes; a controlling pendulum coupled to thefirst side element so as to set an initial gradient of the pressurecontrol plate; and a pendulum blade shaped as a wing to receivesufficient air resistance and coupled to a lower portion of thecontrolling pendulum, where the pendulum blade is configured to movewithin a particular range of angles in vertical rotation by way of airresistance generated during an operation of a vehicle, and the pendulumblade is configured to cause the pressure control plate to move invertical rotation in linkage with the vertical rotation movement.

Advantageous Effects

With an apparatus for automatic control of exhaust pressure of aninternal combustion engine according to an embodiment of the presentinvention, the amount by which the exhaust passage is opened and closedcan be controlled automatically, to increase exhaust pressure duringlow-speed rotation and lower exhaust pressure during high-speedrotation, and thus effectively correspond to the valve overlap, therebyoptimizing the exhaust pressure by immediately responding to the changein output of the internal combustion engine, that is to say, the changein rotational speed. This can increase the efficiency of fuelcombustion, thus substantially decreasing exhaust fumes and saving fuelcosts, and can increase rotational torque not only during high-speedmovement but also during low-speed movement, thus enhancing stability inmovement.

The apparatus can also be easily attached to and detached from anexisting exhaust pipe installed in a vehicle, has a low rate of failurefrom having a simple structure, can be installed conveniently, and has alow cost of production.

Also, according to an embodiment of the present invention, since theamount by which the exhaust passage is opened and closed isautomatically controlled according to the running speed of the vehicleby using the drag generated by a pendulum blade, a driver may drive avehicle with maximum engine efficiency without paying particularattention

Furthermore, an apparatus for automatic control of exhaust pressure ofan internal combustion engine according to an embodiment of the presentinvention also has the marked effect of creating an optimal exhaustpressure environment by conforming easily to various sizes of exhaustpipes installed in a variety of vehicles, as the initial gradientsetting of the pressure control plate and the control of the verticalposition of the pendulum blade can be easily handled.

DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view showing the structure of anapparatus for automatic control of exhaust pressure of an internalcombustion engine according to an embodiment of the present invention.

FIG. 2 is an assembly drawing of FIG. 1.

FIGS. 3 (a), (b) and (c) are sequence diagrams showing the sequence ofmovements of the apparatus for automatic control of exhaust pressure ofan internal combustion engine according to an embodiment of the presentinvention moving according to the running speed of the vehicle.

MODE FOR INVENTION

An apparatus for automatic control of exhaust pressure of an internalcombustion engine according to an embodiment of the present invention isdesigned to automatically control the amount by which the exhaustpassage is opened and closed according to the exhaust pressure,automatically increasing the exhaust pressure during low-speed rotationand lowering the exhaust pressure during high-speed rotation, and thuseffectively responding to the valve overlap.

FIG. 1 is an exploded perspective view showing the structure of anapparatus for automatic control of exhaust pressure of an internalcombustion engine according to an embodiment of the present invention,and FIG. 2 is an assembly drawing of FIG. 1.

With reference to FIGS. 1 and 2, the apparatus for automatic control ofexhaust pressure according to an embodiment of the present inventionincludes: a body 10; a pressure control plate 20; a controlling pendulum30; and a pendulum blade 40.

A core concept of the apparatus for automatic control of exhaustpressure according to an embodiment of the present invention is that thepressure control plate 20 is designed to rotate in correspondence withthe speed of the vehicle within a particular range of angles, thusautomatically controlling the degree to which the exhaust passage isopened and closed, thereby creating an optimal exhaust pressureenvironment according to the output of the internal combustion engine.

The body 10 according to an embodiment of the invention is designed toaccommodate the pressure control plate 20 inside, and to be insertedinto the middle of an exhaust pipe to vary the exhaust pressure. On oneside of the body 10 is an inlet 11 into which exhaust gas emitted fromthe internal combustion engine is entered, and on the other sideopposite to the inlet is an outlet 13 out of which the entered exhaustgas is expelled.

Preferably, the inlet 11 and the outlet 13 should be cylindrical inshape to correspond to the general shape of exhaust pipes, so as toallow easy coupling to exhaust pipes, or be frustoconical, i.e. have ashape like a cone with its pointed end cut off, so as to allow couplingto exhaust pipes of various sizes with greater flexibility.

The pressure control plate 20 according to an embodiment of the presentinvention is in the shape of a thin plate; one side of the pressurecontrol plate 20 is attached to a bar-shaped rotational shaft 25, and itis located between the inlet 11 and outlet 13 of the body 10.

The pressure control plate 20 attached inside the body 10 is designed torotate within a particular range of angles in a direction perpendicularto the ground surface, according to the pressure of the gas emitted fromthe internal combustion engine.

The rotational shaft 25, coupled to one side of the pressure controlplate 20 to allow the pressure control plate 20 to rotate, is designedto have one or more portions protruding through holes 15 a, 15 b in bothsides of the body 10.

The protruding portions 25A, 25B extending through the holes 15 a, 15 bare coupled with a first side element 50 and a second side element 60included on both sides of the exterior of the body 10.

The first side element 50 and the second side element 60 make sure thatthe rotational shaft 25 placed through the holes 15 a, 15 b on bothsides rotate securely in a fixed position without sliding sideways.

The first side element 50 according to an embodiment of the presentinvention has a stepped part 51 protruding in a stepped shape, for thepurpose of connecting the controlling pendulum 30 to the rotationalshaft 25 and of coupling the rotational shaft 25 to the first sideelement 50.

The stepped part 51 has two bolt-fastening holes 53, 55 and a holdinghole 51 a for taking in the protruding portion 25A of the rotationalshaft 25.

The protruding portion 25A of the rotational shaft 25 held inside thestepped part 51 is affixed coupled to the first side element 50 bytightening a tightening-bolt 70, which is inserted and fastened in abolt-fastening hole 53, 55 of the stepped part 51, in relation to thecontrolling pendulum 30.

The controlling pendulum 30, inserted through the bolt-fastening holes53, 55 of the stepped part 51 and clamped there, is a full-thread bolt30, with a helical screw formed into a bar-shaped element. Thecontrolling pendulum 30 serves to couple the rotational shaft 25 to thefirst side element 50 and also makes it possible to control the positionof the pressure control plate 20 (more specifically, to control thegradient of the pressure control plate 20).

The protruding portion 25B of the rotational shaft 25 affixed coupled tothe second side element 60 according to an embodiment of the presentinvention can be coupled by forming the same kind of stepped part on thesecond side element 60 as on the first side element 50 and using twotightening bolts in the bolt-fastening holes of the stepped part, or bytightening a tightening cap 90 in relation to a tightening bolt insertedand fastened to the tightening cap 90.

The pressure control plate 20 according to an embodiment of the presentinvention is included inside the body 10 to be perpendicular to theground or to be inclined at an angle to the ground (in other words,rotated vertically to a particular angle), and the degree of opening andclosing of the inlet 11 will change according to the degree of itsinclination, thus varying the exhaust pressure.

The degree of inclination has to be set differently according to thetypes of engine and exhaust pipe installed in each vehicle, and theinitial gradient of the pressure control plate 20, that is to say, thedegree of inclination of the pressure control plate 20 installed insidethe body 10 when the internal combustion engine is in a stationary stateis set through the following process. (Hereafter, the state in which thepressure control plate 20 rests as meant in the aforementioned sensewill be referred to as the initial gradient.)

The setting of the initial gradient of the pressure control plate 20 isdone on the basis of low-speed rotation of the internal combustionengine. A typical exhaust pipe equipped in vehicles is designed on thebasis of the engine displacement at the time of the greatest output inthe explosion stroke of the engine, and therefore, the efficiency of theengine may be substantially decreased during low-speed rotation.

The apparatus for automatic control of exhaust pressure according to anembodiment of the present invention can be attached to an exhaust pipethat is designed based on engine displacement during high-speed rotationas described above, with the purpose of creating an optimal exhaustpressure environment by way of the pressure control plate duringlow-speed rotation of the internal combustion engine.

Therefore, the exhaust pressure that yields optimal fuel efficiency andoutput enhancement during low-speed rotation of the internal combustionengine may be detected, and the initial gradient may be set as thedegree of inclination that is determined to cause the lift of thepressure control plate 20 placed slantingly on the path of the exhaustgas to produce the optimal exhaust pressure during low-speed rotation,i.e. the exhaust pressure detected above.

Accordingly, once the value of the initial gradient for creating thedetected exhaust pressure is computed, a controlling element is neededby which the pressure control plate 20 maintains a gradientcorresponding to that value within the interior of the body 10.

The controlling pendulum 30 according to an embodiment of the presentinvention is the implement for fulfilling that need, and the full-threadbolt corresponds to this implement; more specifically, the state of theinitial gradient of the pressure control plate 20 is maintained by theweight of the full-thread bolt 30.

In other words, the rotational shaft 25, the stepped part 51, and thefull-thread bolt 30 are designed to move together as a whole, fastenedby the tightening bolt 70.

Accordingly, if no external force is applied to the full-thread bolt 30,the full-thread bolt 30 will tend toward the direction of gravity due toits own weight.

Using the aforementioned characteristics, the pressure control plate 20is first set such that it is located inside the body 10 with the optimalgradient computed through the detection process described above, byrotating the protruding portions 25A, 25B of the rotational shaft 25extending outward from the body 10.

Once this process is completed, the first side element 50 is rotated soas to allow the full-thread bolt 30 to be fastened to the bolt-fasteningholes 53, 55 of the stepped part 51 while the full-thread bolt 30 pointstoward the direction of gravity, then by inserting the full-thread bolt30 and the tightening bolt 70 into the bolt-fastening holes 53, 55respectively and tightening the protruding part 25A, the pressurecontrol plate 20 is made to be located inside the body 10 whilemaintaining the initial gradient.

As described above, in an apparatus for automatic control of exhaustpressure according to an embodiment of the present invention, thepressure control plate 20 is set by a method of conforming the kineticenergy of the exhaust gas to the lift of the pressure control plate 20,and detecting the exhaust pressure that will achieve the greatest engineefficiency during low-speed rotation of the internal combustion engine.This can eliminate incomplete combustion and decreased explosive powerduring low-speed rotation.

Above, a method is suggested of increasing the efficiency of an engineduring low-speed rotation by using the pressure control plate 20according to an embodiment of the present invention to increase theexhaust pressure of the exhaust pipe.

However, while a vehicle is running at a high speed, the time for thevalve overlap to occur decreases significantly and the piston is goingthrough an alternating motion at a very fast speed. Because of this, ahigh exhaust pressure actually becomes an obstacle to the lift of thepiston during the last stage of the valve overlap, and thus lowers theefficiency of the engine.

Consequently, in the case of high-speed running such as theaforementioned, an element for lowering the exhaust pressure is needed.In other words, according to an embodiment of the present invention, thepressure control plate 20, which is obstructing the inlet 11 of the body10, needs to be removed from the inlet 11 as much as possible.

The pendulum blade 40 according to the present invention is an implementfor fulfilling this need during a high-speed run, and by using the draggenerated during the run to remove the pressure control plate 20 fromthe inlet 11 as much as possible, it ensures adequate exhaust passagearea in the exhaust pipe installed in the vehicle, allowing smoothexhaust emission and lowering the exhaust pressure.

Below is a more detailed description.

The pendulum blade 40 according to an embodiment of the presentinvention is designed to move by using the air resistance that isincreased during a high-speed run of a vehicle. Consequently, itsstructure is shaped like a wing or a plate placed perpendicular to thedirection in which the vehicle is going.

Also, the pendulum blade 40 is equipped on an exterior surface of thebody 10, and moves in vertical rotation within a particular range ofangles according to the degree of air resistance generated during therun of the vehicle. The apparatus for automatic control of exhaustpressure according to an embodiment of the present invention isconfigured such that the pressure control plate 20 also moves invertical rotation in linkage with the vertical rotational motion of thependulum blade 40, automatically ensuring adequate exhaust passage areain the body 10 in corresponding manner during high-speed rotation.

In other words, the apparatus for automatic control of exhaust pressureaccording to an embodiment of the present invention is configured tohave the rotational shaft 25, the stepped part 51, and the full-threadbolt 30 moving together as a whole by way of the tightening bolt 70, inorder to have the movement of the pendulum blade 40 interlocked with thepressure control plate 20. The pendulum blade 40 is coupled to a lowerportion of the full-thread bolt 30, so that the pressure control plate20 also moves in vertical rotation in proportion to the degree ofvertical rotational movement of the pendulum blade 40 according to theair resistance, thus immediately varying the amount of opening andclosing of the exhaust passage.

As illustrated in FIG. 2, the pendulum blade 40 can have at least twoplates adjoined at one edge to form a leveled structure and can befastened to the full-thread bolt 30 through the hole 41 formed in oneplate of the pendulum blade 40 and with the use of a pair of tighteningnuts 80 a, 80 b. The position of the pendulum blade 40 can be changed upand down by allowing change in the tightening position of thefull-thread bolt 30 and the nuts, thus allowing the setting of asuitable position of the pendulum blade 40 according to the type of thevehicle.

FIGS. 3 (a), (b) and (c) are sequence diagrams showing the sequence ofmovements of the apparatus for automatic control of exhaust pressure ofan internal combustion engine according to an embodiment of the presentinvention moving according to the running speed of the vehicle.

FIG. 3( a) shows the arrangement of the pressure control plate 20, thecontrolling pendulum 30, and the pendulum blade 40 according to anembodiment of the present invention when an internal combustion engineis in a stationary state.

As illustrated in FIG. 3( a), the pressure control plate 20 is includedinside the body 10, maintaining a particular gradient for creating acorresponding optimal exhaust pressure during low-speed rotation of theinternal combustion engine installed with the apparatus for automaticcontrol of exhaust pressure according to the present invention. Thecontrolling pendulum 30 and the pendulum blade 40 are arranged facingthe direction of gravity.

Afterwards, when the internal combustion engine is in operation and inlow-speed rotation, as illustrated in FIG. 3( b), the pressure controlplate 20 is moved in vertical rotation to a particular angle by thepressure of the gas entering through the inlet 11 of the body 10 and bythe air resistance generated at the pendulum blade 40.

Here, the gradient of the pressure control plate 20 rotated verticallyto a particular angle approaches the gradient detected in theaforementioned process for creating the optimal exhaust pressure inlow-speed rotation.

FIG. 3( c) shows the arrangement of the pressure control plate 20, thecontrolling pendulum 30, and the pendulum blade 40 according to anembodiment of the present invention when the vehicle is in a high-speedrun, or in other words, when the internal combustion engine is inhigh-speed rotation.

As illustrated in FIG. 3( c), the pendulum blade 40 is moved in verticalrotation to a substantially large angle by the air resistance generatedat the pendulum blade 40 and increased by the high-speed run of thevehicle. Accordingly, the pressure control plate 20 is removed from theinlet 11 of the body 10 to a maximum degree, thus maximizing the openingof the exhaust passage.

Accordingly, as the exhaust pressure is automatically lowered againduring a high-speed run (more accurately, as the exhaust pressure isreturned to the original level in the existing exhaust pipe installed inthe vehicle), an exhaust pressure environment appropriate to the maximumoutput of the vehicle is created.

The location for installing the apparatus for automatic control ofexhaust pressure according to an embodiment of the present inventioninstalled in an automobile is as follows.

In general, an automobile comprises the following parts: starting withan exhaust manifold for engine exhaust, an automobile catalyst, a middlemuffler, and an end muffler are joined in assemblage in this order.

As regards the order of configuration of an exhaust pipe, the apparatusfor automatic control of exhaust pressure according to an embodiment ofthe present invention is installed in the area between the automobilecatalyst and the middle muffler, or in the area between the middlemuffler and the end muffler, where it can automatically control theopening and closing of the exhaust passage, thereby creating the optimalexhaust pressure environment according to the output of the internalcombustion engine.

While the spirit of the invention has been described with reference toparticular embodiments using particular terms, the embodiments are forillustrative purposes only and do not limit the invention. It is to beappreciated that those skilled in the art can change or modify theembodiments without departing from the scope and spirit of the inventionas defined by the appended claims. All such variations must not beunderstood separately from the spirit and scope of the invention, andare encompassed by the scope of claims.

1-6. (canceled)
 7. An apparatus for automatic control of exhaust pressure of an internal combustion engine, the apparatus comprising: a body inserted into a middle region of an exhaust pipe, the body having an inlet formed on one side thereof and an outlet formed on the other side thereof opposite the inlet, the inlet configured to receive exhaust gas emitted from the internal combustion engine, the outlet configured to expel the received exhaust gas to the outside; a pressure control plate shaped as a thin plate, the pressure control plate placed inside the body between the inlet and the outlet and installed such as to be capable of rotational movement; a rotational shaft shaped as a bar and coupled to an edge of the pressure control plate to enable the rotational movement, the rotational shaft installed such that a portion thereof protrudes from within the body to without; a first side element coupled to the portion of the rotational shaft protruding out of the body; a controlling pendulum included outside the body to set an initial gradient of the pressure control plate; and a pendulum blade shaped like a wing to receive sufficient air resistance and coupled to a lower portion of the controlling pendulum, the pendulum blade configured to move together with the controlling pendulum by way of air resistance generated during an operation of a vehicle and configured to generate the rotational movement of the pressure control plate in linkage with the vertical rotation movement.
 8. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the inlet and the outlet are cylindrical in shape so as to allow easy coupling of the body to an exhaust pipe, or are frustoconical in shape so as to allow coupling to exhaust pipes of various sizes with flexibility.
 9. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the first side element further comprises a stepped part for coupling the rotational shaft and the controlling pendulum.
 10. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the controlling pendulum is a full-thread bolt having a helical screw formed in a bar-shaped element.
 11. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the rotational shaft protrudes outward at both sides of the body, with the first side element coupled to the rotational shaft protruding outward at one side and a second side element coupled to the rotational shaft protruding outward at the other side.
 12. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 10, wherein the pendulum blade has at least two plate-shaped elements adjoined on one edge to form a leveled structure, and a hole for a full-thread bolt is formed in a surface of the pendulum blade, such that the full-thread bolt inserted in the hole is coupled with the pendulum blade by way of a pair of tightening nuts tightened from above and below, and the vertical position of the pendulum blade is adjustable by selecting the positions of the tightening nuts.
 13. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 9, wherein the stepped part has a holding hole and two bolt-fastening holes formed therein, the holding hole for inserting a portion of the rotational shaft inside, the portion of the rotational shaft inserted inside the stepped part is coupled to the first side element by way of tightening, in relation to the controlling pendulum, tightening bolts fastened respectively in the two bolt-fastening holes, and the rotational shaft, the stepped part, and the controlling pendulum are configured to move together as a whole. 